21012321290 has 8 divisors (see below), whose sum is σ = 37822178340. Its totient is φ = 8404928512.

The previous prime is 21012321289. The next prime is 21012321371. The reversal of 21012321290 is 9212321012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17757961081 + 3254360209 = 133259^2 + 57047^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1050616055 + ... + 1050616074.

Almost surely, 2^21012321290 is an apocalyptic number.

21012321290 is a deficient number, since it is larger than the sum of its proper divisors (16809857050).

21012321290 is a wasteful number, since it uses less digits than its factorization.

21012321290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2101232136.

The product of its (nonzero) digits is 432, while the sum is 23.

The spelling of 21012321290 in words is "twenty-one billion, twelve million, three hundred twenty-one thousand, two hundred ninety".